wingett



J. N. WINGETT.

DISTILLATION FURNACE.

APPLICATION FILED JULY 19, 1911. 1,384,878, Patented July 19, 1921.

8 SHEETS -SHEET I.

J. N. WINGETT.

DISTILLATION FURNACE.

APPLICATION FILED JULY 19. 1917.

Patented July 19, 1921.

a SHEETS-SHEET 4.

Home

l. N. WINGETT.

DISTILLA'HON FURNACE.

APPLICATION mm JULY 19, 1911.

1,384,878. Patented July 19, 1921.

8 SHEE'IS SHEET 5- J. N. WENGETT.

DISTILLATION FURNACE.

APPLICATION FILED JULY I9. 1917.

1,384,878. Patented July 19, 1921.

8 SHEE'ISSHEET 6- John Al W/h Ue/Z 1-. N. WINGETT.

DISTILLATION FURNACE.

APPLICATION FILED JULY 19, 1917. 1,384,878. Patented July 19, 1921.

8 SHEETS-SHEET B- M M /Z 720? 20 5 I l a 209 M //4 //4 X f V 2zzxxa/z'x/ as; New; :2 203 a I \1 2/5 5 [Z a 2/3 avwwwo z UNITED STATESPATENT OFFICE.

JOHN N. WINGETT, OF DENVER, COLORADO, ASSIGNOR TO THE AMERICAN SHALEREFINING COMPANY, OF DENVER, COLORADO, A CORPORATION OF ARIZONA.

DISTILLATION-FURNACE.

Application filed July 19,

To all whom it may concern:

Be it known that I, JOHN N. WINGETT, a citizen of the United States,residing at the city and county of Denver and State of Colorado, haveinvented certain new and useful Improvements in Distillation-Furnaces;and I do declare the following to be a full. clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same, reference being hadto the accompanying drawings, and to the characters of reference markedthereon, which form a part of this specification.

My invention relates to improvements in furnaces adapted for thetreatment of various materials for the purpose of removing certainelements in the form of vapor. The furnace is more especially adaptedfor the extraction of hydrocarbons and other vaporizable materials fromany form of rock, ores, clays or any mineral substance of any characterwhatsoever, as well as for the extraction of hydrocarbons from any formof vegetable. animal or mineral substance.

The furnace is. however, primarily designed for the treatment of oilshale for the extraction of the oil therein.

()ne of the objects of the furnace is to provide a continuous and rapidseparation of hydrocarbons from the various materials in which they arefound, and to this end the furnace consists of a series of superposedunits, whereby the material is subjected to treatment in the variousunits successively, the number of units being such that by the time thematerial has passed through the furnace or downwardly from the top tothe bottom thereof, the hydrocarbons have been completely extracted inthe form of vapor, the lighter varieties being first removed while theheavier are later extracted, the various grades being removed in theorder of their lightness or volatility.

As it takes the material only about ten or fifteenminutes to passthrough the furnace from top to bottom it may be assumed that within tenor fifteen minutes from the time the furnace is started and suppliedwith the material to be treated, the hydro carbon vapors will begin topass off into the proper conduit, whence they are carried to anysuitable condensing apparatus, the latter not being illustrated in thedrawing; and from the time the hydrocarbons begin Specification ofLetters Patent.

Patented July 19, 1921.

1917. Serial No. 181,528.

to leave the furnace, they will continue to pass off as long as theoperation lasts.

Referring now to the specific construction of the furnace, it consistsas illustrated in the drawing of an upright structure upon the top ofwhich are mounted two receptacles adapted to contain the material to betreated. Where this material is oil shale the rock is ground or crushedto a suitable fineness, say forty mesh, and is fed alternately into thereceptacles at the top of the structure, and while it is being fed fromone receptacle to the furnace, the other receptacle is filling, and inthis way the apparatus is continuously supplied with the material to betreated. The furnace part of the structure is arranged below the saidreceptacles and consists of vaporizing and combustion chambers arrangedalternately, a vaporizing chamber being at the top or immediately belowthe said receptacles, a combustion chamber below the vaporizing chamberand so on for any desired number of units, avaporizing chamber andcombustion chamber constituting a single unit as this term is to beunderstood in this specification. The vaporizing chamber contains arotary hearth carrying a series of depending plows, said rotary hearthcooperating with a series of stationary plows supported above thehearth, the plows carried by the hearth extending downwardly therefromand operating upon the material when it reaches the bottom of thevaporizing chamber. The material is fed to the top of the rotary hearthand gradually carried to the outer edge thereof by the stationary plows,during the rotary action of the hearth. This material then dropsdownwardly to the bottom of the chamber where it is acted on by theplows carried by the hearth, and gradually moved toward the center ofthe chamber where it passes downwardl to the next hearth. During thepassage 0 the material through the vaporizing chamber it is acted uponby the heat radiated from the combustion chamber immediately below, andthis treatment is kept up during the passage of the'material through thefurnace, the lighter hydrocarbons being extracted in the uppermostvaporizing chamber and the other grades in the reverse order of theirlightness are extracted successively during the passage of the materialthrough the furnace.

Provision is made for removing the various grades of hydrocarbons fromthe several vaporizing chambers, these hydrocarbons being delivered, asillustrated in the drawing, to an upright conduit whence they may passto any suitable condensing apparatus, as heretofore indicated, the rremoval being facilitated by the introduction of currents of gas from astand pipe arranged on the opposite side of the furnace from thehydrocarbon conduit, the gas 1n1ets being directly opposite thehydrocarbon outlets.

Provision is also made for delivering fuel to the various combustionchambers and for removing the products of combustion therefrom through asuitable stack.

Having briefly outlined my improvement, I will proceedto describe thesame in detail reference being made to the accompanying drawing in whichis illustrated an embodiment thereof. In this drawing:

Figure 1 is a central vertical section taken through the vaporizing andcombustion chambers of the structure, the receptacles at the top beingshown in elevation.

Fig. 2 is a similar section partly broken away, but shown on aconsiderably larger scale, one of the receptacles at the top being alsoshown in section.

Fig. 3 is a vertical section taken through one of the vaporizingchambers at right angles to the sections in Figs. 1 and 2.

Fig. 4 is a horizontal section taken through the furnace on the line 11,Fig. 1, the parts being shown on a somewhat larger scale with parts ofthe rotary hearth broken away to more clearly indicate its structure.

Fig. 5 is an elevation of the furnace viewed at right angles to Figs. 1and 2 and partly broken away. In this view the structure is shown on ascale considerably larger than Fig. 1, but smaller than Fig. 2.

Fig. 6 I is a horizontal section taken through one of the vaporizingchambers, approximately on the line 66, Fig. 1, but on a larger scale.

Fig. 7 is a fragmentary top plan view of a set of plows carried by therotary hearth, the holder for the plows being partly broken away forclearncss of illustration, the structure being shown on'a much largerscale than in the other views.

Figs. 8 is an elevation of the furnace on approximately the same scaleas Fig. 1, but viewed at right angles to the latter. In this view fourcomplete units are illustrated, while the pipe system for the twyers isomitted.

Fig. 9 is a view illustrating automatic means for opening a valve in theconduit through which the hydrocarbons are removed, together with meansfor automatically cutting off the supply of the fuel to th furnace andstopping the motor. In this view provision is also made for operating analarm.

Fig. 10 is a vertical section taken through one element of the structureshown inFig. 9, shown on a larger scale.

Fig. 11 is a horizontal section taken through one of the combustionchambers and illustrating the twyers.

Fig. 12 is a vertical section of the same.

The same reference characters indicate the same parts in all the views.

Let the numeral 5 designate a suitable base or foundation upon which thesuperstructure, consisting of the various furnace units, is mounted.Suitably supported upon this base is the lowermost combustion chamber 6,having top and bottom walls 7 and 8 composed of fire brick or othersuitable refractory material, and inner and outer walls 9 and 10composed of the same material. The top and bottom walls are suitablyspaced to form a chamber of the desired capacity. As shown in thedrawing, cooled bracing pipes 12 are arranged within this chamber, eachbrace consisting of two branches 13 and 14;, the coolin water enteringthe lower branch of the Iirace through a branch pipe 3, and passing outof the upper branch of the brace through abranch pipe 15. As shown inthe drawing, there are four braces in each combustion chamber and theyre ceive their supply of water from pipe mem bers 16 (see Fig. 5). Thelower extremity of each member 16 is in communication with ahorizontally arranged member 17, which is in communication at itsopposite extremities with vertically disposed members 18 which are incommunication through the medium of suitable valves 19 with the inletbranch pipes 1 1,.while the outlet branches 15 of the various braces arein communication with upright outlet pipe members 20, whose upperextremities are in communication with a horizontal pipe member 21, fromwhich leads an upright member 22 for the escape of the cooling liquidafter it has passed through the various braces of the structure. Asillustrated in the drawing the piping just described and illustrated inFig. 5, is duplicated in the front and rear of the furnace (see Fig. 4).

These braces support the top wall of the combustion chamber and also thebottom of the vaporizing chamber next above, thus preventing thisstructure from sagging in the center due to overheating for an extendedperiod. By th employment of the braces any distortion of the structuredue to the aforesaid causes will be obviated, while the bracesthemselves are maintained free from distortion by the cooling effect ofthe water circulating therethrough. These bracing members are adjustableto compensate for slight sagging by means of a nut 215 threaded on thepipe 15 and engaging the wall 11 1. The pipe 15 is rigidly connected tobranch 11 and extends loosely through the wall. Movement of the nut 215will cause the inner end of the brace to move up or down. Branch 13 hasa lug 213 engaging lower flange 208 to brace the lower end of saidbranch.

The various combustion chambers employed in connection with thestructure will all be designated by the same reference character, asthey are substantially identical in structure and a description of oneis a description of all. Each combustion chamber is provided with meansfor introducing fuel in suitable form. As shown in the drawing a burner23 is connected with each combustion chamber and projects thereinto, asshown at 24. Every burner is connected as shown at 25 with a stand-pipe26 from which the fuel supply is taken. As various forms of burners maybe employed in connection with these chambers and as nothing is claimedin this application upon any particular burner construction, theseburners will not be further described in detail.

Furthermore, each combustion chamber is provided with an outlet flue 27for the products of combustion which are delivered to a stand pipe 28constituting a stack for the furnace. Each flue 27 is provided with adamper 29 for regulating the draft.

Arranged above each combustion chamber 6 is a vaporizing chamber 30which has a lining of fire clay or other suitable refractory materialfor its top, bottom and side walls. This lining may be designated in itsentirety by the numeral 31. The bottom lining covers a metal plate 32which is arran ed between the fire brick lining of the combustionchamber and the similar lining of the vaporizing chamber. Vithin thisvaporizing chamber is mounted a rotary hearth 33, which, as shown in thedrawing is composed of top and bottom layers 34 and 35 of highlrefractory material, carrying a filling of re clay 36 or similarmaterial. Each of these hearths 33 is secured, as shown at 37,to ahollow rotary shaft 38, the latter being connected for purposes ofrotation, at the top and bottom with an interior shaft 39, the latter inturn carrying a gear 40 which meshes with a pinion 41 fast on anoperating shaft 42 arranged at the bottom of the structure. Each ofthese hearths carries two sets of depending plows 43 which are connectedwith an arm 44, the plows being inclined to cause the material as thehearth rotates to work inwardly from the outside toward the center ofthe chamber where an o ening 45 is provided for the material uner'treatment to pass into an annular passage 46, from which itisdelivered to a screw conveyer 47 which serves to remove it from thefurnace, a series of blades 4 being connected with the lower end of asleeve 48 surrounding and secured to the hollow shaft 38, for thepurpose of removin the material from the bottom of the anntilar passage46 and discharging it through an opening 49 into the casing 50 of thescrew conveyer.

Each vaporizing chamber 30 is further provided with two sets ofstationary plows 51, which extend downwardly from a supporting arm 52,which is suitably secured to the roof of the chamber. These plows are sopositioned that as the material under treatment enters the top of thevaporizing chamber through an annular passage 53, it is carriedoutwardly as the hearth rotates and finally discharged into an outerpassage 54, whence it drops to the bottom of the vaporizing chamberwhere it is acted on by the plows 43, as heretofore explained. Themanner in which the plows carried by the rotary hearth act upon thematerial in the chamber, is well illustrated in Fig. 6 of the drawing inwhich the set of plows 43 at the right is shown in section, while thesimilar set at the left is shown in top plan view, the plow-carrying armbeing uppermost.

Also arranged within each vaporizing chamber and cooperating with therotary hearth and the plows, are two drags (see Fig. 3) which aremounted upon the hearth and extend downwardly therefrom, while twosimilar drags 255 extend downwardly from the roof of the chamber. Asshown in the drawing each drag is composed of a supporting rod or shaft56 which forms a support for a bottom blade or bar 57 which is connectedwith the rod 56 by arms 58 whose upper extremities terminate in sleeves59 which are loose on the rod, whereby the blade or bar 57 drags so tospeak upon the material on top of the hearth and on the bottom of thechamber, and serves to level said material by filling up the trenches orfurrows formed by the plows. From this it will be understood that thematerial, as it is worked by the plows from the center of the vaporizingchamber to the outer portion thereof and from the outside of the chamberinwardly toward the central discharge opening. is continuously stirred,whereby the vapors formed by the action of the heat radiated from thecombustion chamber, are released and allowed to pass out of the chamberthrough a nozzle 60 into a stand pipe 61 from which they may be carriedto condensing apparatus of any suitable character, as heretoforeindicated.

As illustrated in the drawing, each of the rotary hearths is providedwith a series of metal rings 62, being connected and spaced by radialarms 63 which are indicated by dotted lines in Fig. 4 of the drawing,the radial arms being secured to the hub 64 of the rotary hearth.

Provision is made for facilitating the removal of the vaporized productsfrom the chambers 30 through the medium of blasts of gas of suitablecharacter which may be taken from a stand pipe 264: (see Figs. 5 and 8),which is connected with each vaporizing chamber by a branch pipe 65provided with a controlling valve 66. Suitable gas may be introduced tothe stand pipe 26 1 under any desired pressure, and by the regulation ofthe valve 66 this gas may be introduced into the vaporizing chambersdirectly opposite the outlet nozzle 60 for the vaporized products.Furthermore, the conduit 61 which receives the vapors from the saidchambers, may be and preferably is connected with vacuum or suctionapparatus (not shown) of any desired character which will furtherfacilitate the removal of the vapors and their introduction into thecondensing apparatus (not shown).

Each rotary hearth, as illustrated in the drawing, is thickest at thecenter and tapers toward its periphery, whereby the passage of thematerial from the center to the outside of the chamber is facilitated,since the incline is downwardly. Hence, it will be understood that thestationary plows, or those which depend from the roof or top of thechamber, are of unequal length. In other words, these plows increase inlength from the innermost to the outermost, in order to act equally uponthe material for the purpose stated.

Mounted above the superposed combustion and vaporizing chambers are tworeceptacles 68 which are substantially identical in structure andarranged to be alternately employed for supplying the furnace with thematerial to be treated. Each receptacle has a hopper-shaped bottom 69and an opening 7 0, through which the material 71 passes into the casing72 of a screw-conveyer 73, which serves to carry the material inwardlyto a chamber 76 whence it passes downwardly through an opening 75 to theuppermost rotary hearth 33. The screw conveyer 7 3 is provided with arelatively long stem 76 which extends outwardly and is journaled in asupport 7 7 connected with the bottom of the corresponding receptacle68. To the outer extremity of this stem is secured a sprocket wheel 78which is connected by means of a chain 7 9 with a similar sprocket 80fast on a shaft 81, which is journaled in the wall of the receptacle 68and extends through the upper portion of the latter, its inner extremitybeing equipped with a pinion 82 which meshes with a gear 83 fast on theupper extremity of the shaft 39. Hence, it will be understood, as'thisshaft is rotated through the medium of the mechanism heretoforedescribed, the screw conveyer will be operated to supply the furnacewith material.

It will be understood that but one receptacle is operated at a time forsupplying the furnace. Hence, but one screw conveyer need be inoperation at any one time, but as both are connected with the gear 83,provision must be made for the idle movement of one of the shafts 81.This may be accomplished by loosely mounting each of. the sprockets 80upon its shaft 81 and employing a clutch 84 which is splined on theshaft and adapted to be shifted to cooperate with a corresponding clutchface formed on the adjacent face of the sprocket 80. Hence, when theclutch is in engagement with the clutch face of one sprocket it will bedis connected from the corresponding clutch face of the other sprocket,thus allowing one shaft to turn idly for the purpose stated.

hen the material is fed from one receptacle to the screw conveyer andthence to the uppermost vaporizing chamber, the opening at the innerextremity of the corresponding screw conveyer is closed by a valve 85which is provided with a stem 86 extending upwardly through the top ofthe receptacle and threaded into a nut 186 mounted on a support 87. Thisnut is provided with a hand wheel 88 for convenience of manipulation. Inorder to facilitate the operation of the valves of these receptacles,the struc- .ture is provided with a platform 89 which is supported bythe receptacles 68 and is surrounded by a railing 90. An additionalrailing 91 is also arranged upon a lower platform 92 at the base of thereceptacles. This platform also serves to enable the operator or personin charge of the furnace to look after the mechanism thereof. Suitableprovision, as a ladder structure (not shown), will be provided to enablethe operator to reach these platforms and descend therefrom ascircumstances may require.

It is my intention to maintain the entire vaporizing chamber structureof the fur nace under vacuum in order to facilitate the removal of thevapors extracted from the material under treatment. It will beunderstood from the description already given that all of the vaporizingchambers are in communication with one another by way of annularpassages surrounding the hollow shaft; and in order to maintain thisvacuum I provide seals 93 and 94 at the top and bottom of the furnace.The seal 93 is composed of a cup 194 having an annular open-- ingcontaining a quantity of mercury 95. This cup is secured to a plate 96formed integral with the base 97 upon which the receptacles 68 aremounted. A bushing 98 .is arranged between this cup and a tubular member99 which extends upwardly from the uppermost rotary hearth around theupper portion of the hollow shaft 38. To the upper extremity of thehollow shaft is secured, as shown at 100, an inverted cup 101 which dipsinto the. mercury in the companion cup 194, thus forming a seal at thetop of the vaporizing chamber structure of the furnace.

The seal 94 at the bottom, is composed of a cup 102 containing aquantity of mercury 103. This cup has an interior sleeve which fitsclosely around the adjacent portion of the shaft 39, this sleeve beingconnected with the body of the cup by a. web 104. This web is connectedby means of suitable fastening devices as stud bolts 105 with the lowerextremity of the hollow shaft 38. A depending member 106 extends intothe mercur in the cup 102, this depending member bem secured, as shownat 107, to a base pla 108, forming a chamber 109 around the hollow shaftand forming the bottom of the annular passage 46 in which the rotaryblades 4 are arranged. The lower extremity of the rotary sleeve 48engages the base plate 108, but would not form a sufliciently ti htjoint to seal the vaporizing chambers su ciently to permit them to bemaintained under vacuum, consequently the seal 94 is employed.

In order to cool the shaft structure of the furnace, the lower portionof the shaft 39 is formed hollow and a pipe 110 inserted therein throughwhich water may be introduced into an annular space 111 between theshaft 39 and the hollow shaft 38, this water entering the space 111through an opening 112. This water rises in the space 111 and enters anopening 113 in the upper extremity of the shaft 39 and, passes out atthe upper extremity of the shaft from which it may be carried away byany suitable means.

The outer shell of the furnace is composed of a series of cylindricalsections 114, said sections being connected by suitable fasteningdevices 115, the metal plates 32 between the fire clay linings beingalso secured by these fastenings at 206. The central portions-of theseplates are bolted to lugs on the tube 45 and 53 as shown in Fig. 2. Anannular flange 208 on each plate spaces the fire clay lining of both thevaporizing and combustion chambers from the wall sections 114 to furnishinsulating spaces 209.

For safety purposes, the stand pipe or conduit 61 is provided above theuppermost nozzle 60 with a valve 116 which normally ongages a seat 117,against which the valve is held by a spiral spring 118 which surroundsthe stem 119 of the valve, one extremity of the spring bearing againstthe valve piece while the other extremity engages a stop 120 securedwithin the pipe and; carrying spider arms 121; whose outer extremitiesare in direct contact with the pipeand fast therein. The stem 119 ofthis valve is freely sl-idable in the stop 120 and to its upperextremity is connected, as shown at 122, the inner slotted: extremity ofa lever 12.3 which 619;! through an opening; 124 formed inanextem sion125 of the main-stand. pipe or conduit 6'1, this extension beingconnected to the top of the pipe by bolts 126 which pass throughperforations formed in the meeting flanges of the two connected members.This lever 123 is fulcrumed, as shown at 127, on ears 128 with which theextension 125 is provided. To the outer extremity of this lever isconnected a weight 129 whose stem 130 is secured to the lever, as shownat 131. This lever carries an electrical contact 132 which is arrangedin suitable proximity to a companion contact 133 mounted on a stationaryarm 134 carried by the extension 125. When a vacuum is employed thespring 118 aids in holding the valve 116 on its seat, but the force ofthe vacuum actually controls it by drawing it into the seat when strongenough for proper operation of the machine. When the vacuum becomes tooweak, the weight 129 controls and unseats the valve. Normally, or whenthe valve 116 is seated, these contacts 132 and 133 are separated, butin the event that pressure within the furnace of any considerablemagnitude, or such as might prove dangerous should exist, or the vacuumwhen used becomes too weak, the valve will be unseated in which eventthe contact 132 will be brought into engagement with the contact 133 andclose a circuit through a magnet 135 of the solenoid type. The core 136,or movable part of this solenoid, is connected at its upper extremity,as shown at 137, with a slotted end of an arm 138 which is connected, asshown at 139, with a. stem of a valve piece 140 which is arranged withinthe pipe 26 which supplies fuel to the furnace, the said valve beinglocated between the source of supply and the inlets communieating withthe combustion chambers. On the opposite side from the arm 138, is asecond arm 141 which carries a weight 142 of suitable mass to normallybalance the valve in the open position, or in position to allow the fuelto ass to the furnace through an opening 143. cu, however, theelectrical circuit is closed through the coil 144 of the solenoid 135,the bar 136 will be raised and the valve piece 140 moved sufliciently toclose the valve or cut off communication therethrough with thecombustion chambers.

The lower extremity of the movable bar or core 136 is connected, asshown at 145, with an insulating part 146, the latter being connectedwith a metal contact 147 which extends into an insulating casing 148,the bar 147 being itself surrounded by insulation 149 which is movablewith the bar. The lower extremity of the contact bar 147 is normally inengagement with acontact screw 150, which is threaded into the bottom ofthe insulating casing 148 and protrudes into the lower part of a chamber151 formed 1n the inmilatiug casing and adapted to receive the bar 147with its insulating covering 149. When the contact 147 is in engagementwith the screw 150, the electrical circu t is closed througha motor (notshown) for operating the machine through the medium of the shaft 42 andthe gearing connections heretofore described. But, as soon as the coilof the solenoid is energized and acts upon the bar 136 to lift thelatter and close the valve 140, it also disengages the contact bar 147from the screw 150 and breaks the circuit, thus stopping the motor.Again, as the con tact bar 147 is raised by the magnetic influencegenerated in the coils of the solenoid, a spring contact 152 which issecured to the bar 147 by a screw 153, is brought into engagement withthe inner extrem ty of a contact screw 154, which is mounted on theinsulating casing 148, thus closing a circuit 3 through an alarm, whichas illustrated in the drawing consists of an ordinary bell 155, thusgiving warning to the person in charge of the machine or anyone in thevicinity thereof.

Normally, or when the valve 116 is closed, the electric circuit in whichthe motor (not shown) is located, may be traced as follows: A conductor156 may be said to have one extremity connected with a suitable sourceof current (not shown) while the other extremity leads to a contactscrew 157 which is threaded into the contact bar 147. Hence, the currentafter leaving the conductor 156 will pass through the screw 157, throu hthe contact bar 147 the screw 150, a con uctor 158, and thence through arheostat 159, and finally through a conductor 160 to the motor (notshown). From the motor a conductor 1.61 leads to the other pole of theelectrical source (not shown).

Now, in the event that the valve 116 is unseated, as heretoforedescribed, whereby the two contact screws 132 and 133 are brought intoengagement, the path of the current may be traced as follows: Commencingat a point 162 in the conductor 156, a conductor 163 leads to thecontact screw 132 from which the current passes to and through thecontact screw 133, a conductor 164, a resistance coil 165, a conductor166 and thence to one terminal of the coil 144. From the op positeterminal of this coil a conductor 167 leadsto the conductor 161, whencethe current passes to the opposite pole of the electrical source. Assoon as this happens, the magnetic influence developed by the coil 144,acts to lift the bar 136, whereby it is disengaged [from the contactscrew 150, thus breaking the motor circuit. As soon as this occurs thecontact spring 152 is brought into engagement with the contact screw154, and

the circuit is then completed through the electric bell 155. The path ofthe current will be as follows: From the main conductor 156 to thecontact screw 157 ,thence through the contact bar 147, the screw 153,the contact spring 152, the screw 154, a conductor 168, a IiSiStancecoil 169, to the bell and thence from the bell through a conductor 170to the main conductor 161 and thence to the opposite pole of theelectrical source (not shown). 7

From the foregoing description the use and operation of my'improvedfurnace will be readily understood. Assuming that the material to betreated is oil shale, for ex ample, this material is first ground orreduced in any suitable manner to the desired fineness, say 40 meshapproximately, although it must be understood that the particular meshto which the material is re duced before passing it to this machine fortreatment, will depend altogether on the kind of material and variousother conditions which may be present, and, therefore, must be givenconsideration. This material it will be assumed is placed within thereceptacle'68 located to the right in Figs. 1 and 2 of the drawing, thevalve being open, as shown in Fig 2, to allow the material as it isacted on by the corresponding screw conveyor to pass into the chamber 74and thence downwardly through the opening 75 to the top of the'upmostrotary hearth 33. By virtue of the fact that all of the rotary hearths33. are connected with the central shaft structure composed of the parts38 and 39, as this structure is rotated a corresponding movement will beimparted to all of the rotary hearths. Hence, it will be assumed thatthese hearths are inmotion. Hence, as the material is fed to theuppermost hearth, as the latter rotates, the material will be carriedoutwardlygthereon through the me dium of the stationary plows 51, whichare so arranged as to gradually carry the material outwardly anddischarge it beyond the periphery of the hearth, whence it passesdownwardly to the bottom of the hearth, from which position it isgradually carried inwardly through the medium of the plows 44 carried bythe rotary hearth and finally discharged through an annular opening 53,to the rotary hearth of the vaporizing chamher next below, where theoperation heretofore described will be repeated, the material beingsuccessively subjected to the action of the heat radiated from thecombustion chambers, until it has passed through the entire furnace, theresidue or gangue being finally removed by the screw conveyer'50 whichis arranged below the lowermost combustion chamber, as heretoforedescribed. While the material is passing through each vaporizingchamber, it is alternately furrowed by the plows and leveled by thedrags and during this plowing and leveling operation, the vaporsproduced by the action of the heat upon the material under treatment,are thrown off from the said material and pass from the vaporizingchamber through a nozzle 60 to theeonduit or stand pipe 61, asheretofore explained, lhe vapor is produced in the uppermost vaporizingchamber contains the li htest or most volatile portion of the hyrocarbon substance of the material, the action of the heat upon thismaterial serving to produce an eruption, whereby the hydrocarbon in theform of vapor is removed from the material, in the various vaporizingchambers and removed therefrom in the reverse order of their volatility,that is to saythe lighter from the uppermost chamber, the next lightergrade from the chamber next below, and so on.

As these hydrocarbon vapors pass from the different vaporizing chambers,it is not necessary that they should all pass to a single stand pipe orconduit as illustrated in the drawing, since each grade may beseparately removed and conducted to a condenser, whereby the variousgrades are kept separate from one another, thus avoiding the necessityfor separating or refining the entire product in bulk as would berequired where all of the grades pass into the same conduit and aredelivered in bulk to the condenser.

In the event that there should be pressure in the vaporizing chamberstructure of the system, I have made provision whereby this pressure maybe relieved through the opening of the valve 116 in the stand pipe 61,and whereby the opening of this valve through the medium of suitableelectrical connections, will close a cut-off valve in the fuel supplyconduit, break the circuit of the motor for operating the shaft withwhich the rotary hearths are connected, and also close a circuit throughan alarm bell, all of which has heretofore been explained in detail.

Having thus described my invention, what I claim is A furnace comprisingsuperposed vaporizing and combustion chambers alternately arranged,linings for said chambers, outer shells for said chambers, horizontalplates lying between the top and bottom walls of adjacent chambers,extending between the outer shells of adjacent chambers and spacing theshells from the linings to provide insulating spaces therebetwecn.

In testlmony whereof I affix m si nature.

JOHN N. Wl NG lETT.

